Vaulted cellar insulation in soft stones

[dax113]

Hello,

I live in a 80th century house made entirely of stone, which had been renovated / rebuilt in the early XNUMXs.
The cellar is vaulted, in soft stones, cement floor, and is located below road level. The temperature never drops below 10 ° even in the middle of winter. The humidity fluctuates between 55 and 70 ° depending on the weather.
During the renovation of the house by the former owners, underfloor heating with electrical resistances was installed, poured into the cement slab of the RDV, above the cellars. Its main role was basic heating (like 14-15 °) and to block the cold that rises from the cellar.
Today, I have the impression that certain resistances are HS - decrease in interior comfort, increase in the electrical consumption of the tiles with a decrease in heat return. In addition, I heat myself with a wood stove and a Godin, the reversible radiators (heat pumps) being the auxiliary heaters (which I use more than before ...).
It is clear that I spend more electricity on the tiles than they release heat in recent years. But not using these tiles at all results in an unpleasant penetrating cold which is not frankly compensated for by other heat sources (the cold rises from the tiled floor and the cellar). On the other hand, in summer, even by heat wave where it can be very hot in the rest of the house, the ground floor remains pleasant and never exceeds 26-27 ° in the worst summer seasons.
It would be a shame to conceal the soft stone vaults of the cellar (our old people even knew how to do things well!), But I'm starting to think for myself.
I need your advice on how to insulate the cellar to prevent this coldness from going up in the house (thus allowing me to no longer have to use the tiles) without doing this titanic work (not the financial means) or trying to aim for a perfect result (this house will ** never ** be a perfectly isolated dwelling and even less with positive energy - we must remain reasonable and realistic!).
I specify that I am not able to carry out this work by myself in order to control the cost!
Thank you for your good advice.

[raymon]

It seems that the ground is poorly insulated. A "not very expensive" solution would be to make a wooden floor with insulation between the joists, but this risks reducing the height of the room. To preserve the "freshness" of the cellar, you can make a concealable hole between the cellar and the living room, a sort of Canadian well.

[Obamot]

It is not possible to do this without isolating the heating mat and therefore making the problem worse, unless it is decided to definitively condemn underfloor heating !!! ????

To "insulate the ground" without condemning the underfloor heating, it is necessary to insulate from below, but that will not eliminate the thermal bridges with the facade walls, which themselves "pump heat" much more than '' a 10 ° C cellar when outside it is between 9 ° C and (below) <0 ° C

Hello,

Hello and welcome.

I live in a 80th century house made entirely of stone, which had been renovated / rebuilt in the early XNUMXs.
The cellar is vaulted, in soft stones, cement floor, and is located below road level. The temperature never drops below 10 ° even in the middle of winter. The humidity fluctuates between 55 and 70 ° depending on the weather.

It is therefore a good cellar, not too humid!
How do you use it? Do you have pictures?

During the renovation of the house by the former owners, a floor heating with electric resistances was installed, poured into the cement floor of the ground floor, above the cellars. Its main role was basic heating (like 14-15 °) and to block the cold that rises from the cellar.

It is never the cold that rises but the heat that escapes ... (thermodynamic law, common error, I do not blame.)

Today, I have the impression that certain resistances are HS - decrease in interior comfort, increase in the electrical consumption of the tiles with a decrease in heat return. In addition, I heat myself with a wood stove and a Godin, the reversible radiators (heat pumps) being the auxiliary heaters (which I use more than before ...).
It is clear that I spend more electricity on the tiles than they release heat in recent years. But not using these tiles at all results in an unpleasant penetrating cold which is not frankly compensated by the other heat sources

As you age, your perception of cold intensifies. You might want to try a liver-protective diet, as a good liver regulates temperature better. Obviously this implies a healthy lifestyle, especially no alcohol (nor tobacco) no excess sweets, a good acid-base balance (lots of vegetables, legumes, potatoes and other steamed root crops), little or no of meat products. And above all very little mineralized drinking water <150mg / l and very slightly acidic PH (very important.)

Your heaters may be working well, but it's the cost of electricity that has gone up. The first thing would be to get a laser thermometer, then take measurements from the cellar every 30 cm in a temperature reading in the form of a checkerboard. One night with heating on, another measurement another night with heating on. We find these thermometers around 37 € on the shop https://www.econologie.com/shop/thermometre-infrarouge-laser-discount-p-593.html?search_query=thermometre&results=27 (at this price it's a gift ...)

(the cold rises from the tiled floor and the cellar).

In a building of this type, as long as there is no ITE, there is heat loss almost everywhere: ground at ground level and through cellars, front walls, floors, wall perpendicular to the facade (and in particular cross walls), screeds, roofing. Obviously all these losses cannot be compensated for by a parsimonious heating which should fight against important thermal bridges (what you seem to have with your cellar, but not only, perhaps you have a good number of cement screeds on the ground floor which extend on a sidewalk or beyond the high-wind of the entrance and any access door from the outside, these are all possibilities of extensions of these thermal bridges, as also the walls of the cellar - and therefore the foundation - included, it's all together that pumps your heat)

On the other hand, in summer, even by heat wave where it can be very hot in the rest of the house, the ground floor remains pleasant and never exceeds 26-27 ° in the worst summer seasons.

This is due to the fact that there, the thermal bridges play in your favor, the night-time phase shift of cooling having sufficient thermal inertia in the walls and everywhere, to compensate / surpass the solar warming ...

It would be a shame to conceal the soft stone vaults of the cellar (our old people even knew how to do things well!), But I'm starting to think for myself.

It is not so much that they badly conceived the buildings that at the time we heated up block by beautiful outbreaks during the day: because wood (fuels) were not expensive ... The walls stored a gentle heat and restoring it overnight until morning, or a new outbreak took over and restarted the cycle ... It could pinch a bit, it sometimes froze inside, but we were used to it. 14 ° C was perceived as really comfortable ... but we spent a lot more physically than today. And when the money was lacking for fuel, we approached the fire ...

I need your advice on how to insulate the cellar to prevent this coldness from going up in the house (thus allowing me to no longer have to use the tiles)

I doubt that the only insulation of the cellar ceiling will overcome these unpleasant sensations ...
You have to be honest, the possibilities of thermal bridges are numerous and must all be treated simultaneously, if you want a significant gain in comfort (and the reduction in the related heating costs ...). Otherwise, there is no mystery, it is necessary in this type of building to install a mass stove to heat "in the old way" in an "economical" way (count a resistance on the ground of 2T, placed in the center of the house , a simple wooden support post in the cellar is sufficient.)

without doing this titanic work (not the financial means) or trying to aim for a perfect result (this house will ** never ** be a perfectly isolated house and even less positive energy - we must remain reasonable and realistic! ).

There is no mystery, it is necessary to remain humble, it is not so much us who decide the solution to bring, that its prolegomena do not impose themselves on us ... (sorry for the ugly word.)

I specify that I am not able to carry out this work by myself in order to control the cost!
Thank you for your good advice.

In principle, it goes without saying, the solutions of the public works BAT are by nature always wanted as "industrial" therefore "economic". But on the other hand here, we answer the technical questions ONLY (otherwise we risk losing objectivity!) In the sense that we will not move towards a solution taking into account a "budget" (this cannot be our concern. basic). That's not really a notion that you can master when you have thermal bridges in your face. We cannot invent low cost solutions that do not exist, we have to be realistic. We can limit the damage ... But undertaking work that is too "cheap" can prove to be very costly in the long term (for example the heat pumps precisely, which had already been a solution of this order, I mean of the "lesser evil" , the investment in a heat pump and its installation can represent half the cost of thermal insulation ...)

[raymon]

Prolegomena: plural masculine noun; from the Greek pro, before, before and from legein, to say.

It is a long introduction placed at the head of a work or else all the concepts preliminary to a science. It is always used in the plural.

[Obamot]

Yes, I wrote it in the plural so why are you taking me back? What a tease this Raymon ^^
(But still: CF prolegomena of solution => science = first principle of thermodynamics >>> )

According to the first principle of thermodynamics, during any transformation, there is conservation of energy.

In the case of closed thermodynamic systems, it is stated as follows:

« During any transformation of a closed system, the variation of its energy is equal to the amount of energy exchanged with the external environment (by thermal transfer (heat) and mechanical transfer (work) »

solution in the singular because there may be only one => the mass stove!
[Joke "ON" mode] Unless you are thinking of installing the e-dog? ^^

[dax113]

Thank you for your return Obamot, I try to take up the various aspects of your message.

- thermal bridges. It is sure that the house has plenty of them. It would be impossible to settle all or most of them (technically and financially)
- the feeling of cold which rises (see. the heat which leaves!): Certainly, you are right - and the house retains heat badly, it is obvious. But the feeling of cold from the floor (terracotta tiles, laid on a concrete screed in which the resistors are now partially HS) which "rises" is very real nonetheless, although technically, of course, you are right.
- mass stove in the middle of the room - uh, difficult. The house is 3 floors, over 13m high and in the center we already have the chimney flues (wood stove, godin, and upstairs chimney in living room - so 3 separate conduits in a chimney which is right in the center from the roof - if my description is understandable).
- of course the price of electricity (well all taxes rather) has increased, but I look at the consumption itself during the heating periods. And it increased while the return of heat by the tiles decreased. This is partly due to the more frequent use of heat pumps. But I wonder if ** tiles with HS resistors consume more than an installation without partial breakdown **? Hard to measure - they charge HC at night to restore the day.
- my use of the cellar (in fact there are two cellars side by side) is storage, washing machine, etc. I don't live there
- I do not have many other possibilities, from the little that I know of the possible options (and certainly, an inexpensive solution is often, like everything, already too expensive - but I must find a happy medium unless I win lottery), that try to isolate a little bit the cellars (walls and ceilings or well? Knowing that the ceilings are vaults..With what / how?) or to demolish the whole slab of the ground floor to change the resistances and to have more effective ones (mash, what a site it would be!)

In short, I sometimes have the discouraging impression that it's mission impossible (er everything is possible with time and means but good) ...

And certainly, we feel more cold as I get older (thank you for reminding me !!!), but I base myself on real data too (thermo and hydro), not just on the feeling . The hot green tea is ready

[izentrop]

Underfloor heating without insulating underneath, is that possible?
The heat losses are mainly from above and the walls, it is rather at these levels that insulation must be accentuated.
The simplest being from the outside if you don't want to do any work inside.
And a floor covering that is less cold to the touch

[dax113]

You are right, Izentrop. So the roof is well insulated, the windows too. It's already that!

Insulating from the outside is certainly simpler, but (sacrifice, I recognize) covering these magnificent stones of almost 600 years would be criminal (well, for lovers of old stones). This would not solve all of the thermal bridges anyway which are responsible for the majority of the heat loss. I am well aware of this.

For underfloor heating without insulation - the renovation took place between 1978 and 1981 - a completely different era. If there is insulation of the floor before the tiles, it is not felt at all!

Adding a less cold floor covering is an option (hello maintenance when you come in and out of the garden), but if the heat of the tiles is already barely noticeable, I fear that "adding a layer" would block any return of their heat. . Notice?

Nothing to consider at the level of the cellar ??

My goal is not perfect insulation or perfectly optimized, efficient and environmentally correct heating. My goal is to compensate for the obvious decrease in the return of heat from the tiles and to limit the spread of feeling of cold rising from the cellar.

I repeat my question on the electrical consumption of slabs of which certain resistances are dead, because that calls me.

[Obamot]

No, not at all, according to your description of the situation, your budget will never allow you to undertake an ITE. Thus in your situation and in all cases the "magnitude of eXergie" obtained in your building, will be VERY LOW unusable, completely unusable, I congratulate you for having understood this immediately this point has been fully understood. This is why I fully share your opinion, in your case it is necessary to make the minimum on the insulation side, it is useless! And drop the idea of ​​rehabilitating lame heating solutions.

Underfloor heating without insulating underneath, is that possible?

Good remark from Izentrop. Not only is it silly, but it should only be offered in central heating and of course insulated from below (the only investment in insulation to consider in your home, apart from double glazing). Electric heating is an ineptitude, by the ground or by heat pump, this is also why you have to stop that to get out of nuclear power.
And you stop investing in it, it will be a financial pit!

Thank you for your return Obamot, I try to take up the various aspects of your message.

- thermal bridges. It is sure that the house has plenty of them. It would be impossible to settle all or most of them (technically and financially)
- the feeling of cold which rises (see. the heat which leaves!): Certainly, you are right - and the house retains heat badly, it is obvious. But the feeling of cold from the floor (terracotta tiles, laid on a concrete screed in which the resistors are now partially HS) which "rises" is very real nonetheless, although technically, of course, you are right.
- mass stove in the middle of the room - uh, difficult. The house is 3 floors, over 13m high and in the center we already have the chimney flues (wood stove, godin, and upstairs chimney in living room - so 3 separate conduits in a chimney which is right in the center from the roof - if my description is understandable).
- of course the price of electricity (well all taxes rather) has increased, but I look at the consumption itself during the heating periods. And it increased while the return of heat by the tiles decreased. This is partly due to the more frequent use of heat pumps. But I wonder if ** tiles with HS resistors consume more than an installation without partial breakdown **? Hard to measure - they charge HC at night to restore the day.
- my use of the cellar (in fact there are two cellars side by side) is storage, washing machine, etc. I don't live there
- I do not have many other possibilities, from the little that I know of the possible options (and certainly, an inexpensive solution is often, like everything, already too expensive - but I must find a happy medium unless I win lottery), that try to isolate a little bit the cellars (walls and ceilings or well? Knowing that the ceilings are vaults..With what / how?) or to demolish the whole slab of the ground floor to change the resistances and to have more effective ones (mash, what a site it would be!)

In short, I sometimes have the discouraging impression that it's mission impossible (er everything is possible with time and means but good) ...

And certainly, we feel more cold as I get older (thank you for reminding me !!!), but I base myself on real data too (thermo and hydro), not just on the feeling . The hot green tea is ready

Basically you would like to find a solution without changing anything in your conception of things well I wish you courage!

Obviously if you put a mass stove (which exists with an integrated vegetable patch) you only keep the chimney (a special insulated flue coming inside this old chimney, so it can no longer be used for something else if there is only one! Anyway, it is efficient enough a 9kW so that you do not need anything else. It is the only solution in your case, where the result will be guaranteed. With the key a reduction in heating consumption of more than 2/3 (and rather 3/4) compared to your current situation (because indeed you completely forget the heat pump and other electric underfloor heating) ... no longer need to replace a CAP out of breath and total heresy in your case, so there you will already save between 10 and 000 € and possibly 20 to 000 € to rebuild the chappe with the change of electrical resistances ...) the only thing to undertake in your case, will be to insulate the ceiling of the cellar ... But if you do that, you will not feel much difference (I mean without mass stove that will replace your current stove), because it is calculated in size eXergie, it will be very low when it comes to heating a colander ...

After it is you who see, but good luck for your project in any case!

PS: there are group courses to make a mass stove yourself! It goes as follows, the group sets up mass stoves in turn in each of the participants' habitats, one week they come to your place, the other you go to another participant to lend a hand (and so on) , always with a pro internship supervisor who oversees operations ...

[raymon]

To insulate a vault it is not very simple (thermal bridge), remaking from above with good insulation seems to me more simple and effective an insulated and oiled parquet is durable if it is of good quality and especially impression of warm, an insulated screed and tile would do the trick but probably more expensive. Electric underfloor heating forgotten.